


Castiel

by Keysmasher



Series: Good Girl [15]
Category: Supernatural
Genre: Anal Sex, Angst, Cheating, Cliche, F/M, Foursome - F/M/M/M, Kissing, Light Bondage, M/M, Multi, Oral Sex, Possessive Sex, Riding, Silly Sex, Sleep Sex, Threesome - M/M/M, You breed with the mouth of a goat, bareback, make-up sex
Language: English
Status: Completed
Published: 2014-05-15
Updated: 2014-05-15
Packaged: 2018-01-24 23:20:30
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,717
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1620611
Author URL: https://archiveofourown.org/users/Keysmasher/pseuds/Keysmasher
Summary: <blockquote class="userstuff">
              <p>Castiel is new to being human, and sometimes he makes mistakes and comes to the wrong conclusions.</p>
            </blockquote>





	1. Betrayal

**Author's Note:**

> We all know everyone thinks Cas is attractive. So of course I had to do something with that. Mild dub-con - Cas initiates sex while Dean is asleep, but Dean doesn't mind at all.
> 
> This is my first time writing Cas, and it came out kind of...distanced? IDK. And I finally realized that I'd never explained why the boys were suddenly able to get hard over and over - I thought it was implied pretty heavily, but that one commenter made me realize it had never been confirmed, so.

Castiel would be the first to admit he was unused to humanity, but after several years of actually being human, he was much closer than he had once thought he would ever become. He'd certainly never thought he would Fall for the privilege of marriage and children.

Dean told him he was doing fine with being human, and it was his own anxiety getting the in the way, and Cas tried to believe him. Maria told him she loved him, and Cas definitely believed her. Sam smiled and kissed him and told him he wanted him, and Cas was hardly able to deny that, arranged as the two of them were sucking each other off. Dean and Maria were cuddling in the living room, watching TV with the kids; as fantastic as it was to have all four of them together, sometimes someone just wasn't in the mood for sex, and sometimes two people weren't. Dean and Maria weren't going to begrudge Cas and Sam for fucking while they stayed outside, and they knew they could join at any point (and that had happened before, with two or three of them in bed and then someone else joined in). The only time any of them would have a problem with it is if they fucked someone other than the four of them.

So far, that hadn't been an issue. None of them were expecting it to become one.

Sam groaned around Cas's dick, drawing his attention back to the matter at hand, and Cas shuddered at the vibration, whimpering around Sam's in return, and somehow they ended up both making noises around each other that slowly got stranger until Sam made the noise of a sheep with the head of Cas's dick in his mouth and they both started laughing, rolling away from each other until they could control themselves again.

Sam wheezed, "Hey, you remember what you told us was funnier in Enochian a couple years back?"

Cas considered. "You breed with the mouth of a goat?"

Sam lost it again, managing to get 'baa' out through his laughter, and Cas smirked. Sam was on his back now, not his side, and Cas dove in to suckle at the base of his cock, careful not to let Sam's flailing legs kick him too hard.

Later, Cas woke in the middle of the night with a full bladder. He relieved himself and stumbled back into the bedroom, but before he fell back into bed, he looked at the family they'd cobbled together from the shells and shadows they'd all once been, baby monitors on the bedside tables standing in for the kids in the other room.

He truly could not be happier.  
***  
Cas's life was simple now. He was done fighting in Heaven's wars, and he was done leading others. His life consisted of playing with his children - who cared if they didn't know who the biological father was? - doing his schoolwork, and tutoring the high-schoolers who came to him for math help. Compared to the difficulties of strategizing a war and running Heaven, domesticity was straightforward.

It was also much more rewarding than he'd anticipated. Who would have thought playing with stuffed animals and small children all day would be more fulfilling than running a garrison of angels?

Anna's first word was 'Cas'. Aspian's was 'Dean'. Anna started walking at seven months, Aspian at eight once he saw how his sister moved. By ten months they could walk short distances unaided, and by fifteen they were running around terrorizing the dogs. Gnat and Basket would disappear into the yard whenever Anna and Aspian were moving, which was a marked change from when they'd only go outside to do their business or to play with the tennis balls Cas would throw for them. The dogs themselves had grown into two-foot balls of energy. Gnat's head and paws were still too damn big for his body, which Maria said meant he'd probably keep growing, but his head was already level with the middle of Cas's thigh - how much bigger could a dog get?

Classes at the college continued. From what the students around him said, the math was getting progressively harder, but for him, the numbers and equations fit together with the same simplicity that had come to permeate his life.

But of course, simplicity couldn't last forever.

It started, as such things do, with a situation romance novels typified as an innocent beginning: a group project. Cas's group had three others, two of whom were women. Mark and Johanna were taking the class for an engineering major; Lucia was attending because she, like Cas, was majoring in math. Professor Mathews assigned the groups their topics - Cas's group was to do a powerpoint on boundary functions and curvilinear convergence - and dismissed them to research. They immediately came together at a table.

"Ted Kaczynski did his thesis on this, you know," Lucia said with relish.

"Who?" Mark asked.

"The Unabomber," Johanna said impatiently. "It was how they caught him. Linguistic similarities."

"Huh." Mark looked thoughtful for a moment before he pulled out his notebook. "So what do we know about this?"

The discussion lasted for another hour, until the allotted time was over. Cas smiled politely as they split apart, shivering a little in the chill of the air; it was unreasonably cold for a night at the beginning of March. Cold was something he'd had to learn to adapt to - as an angel, he had never noticed the temperature unless it was extreme enough to harm his physical form.

Of course, learning to adapt had involved quite a bit of time spread out under a blanket with his partners, so it hadn't been too much of a hardship.  
***  
Wednesday morning he woke to Dean throwing an arm over his chest and mumbling incoherently into his bicep, top lip dragging along the skin as it rode up to expose the top row of teeth in his slack mouth. The clock on the dresser said it was just after seven; he could hear the muffled sounds of Maria in the bathroom, dressing and brushing her teeth. She must be running late.

He traced a finger fondly down the side of Dean's face, remembering doing the same action many times, always when he was asleep. Once, Dean would have rather killed someone than hugged them, but now he mumbled and closed his mouth, head lolling until it was mushed into the pillows beneath them. Cas chuckled and moved to smooth his hair instead.

A minute and a half later, Maria came out of the bathroom, hurriedly slipping her feet into shoes by the door. "Morning," Cas said quietly.

She threw him a smile, no less dazzling for the haste and distraction. "Morning. Changed and fed the kids already."

Cas glanced at the monitors, surprised. "I didn't hear them wake up."

"I got in there right as Anna started fussing." Maria came around to the side of the bed and pressed a quick kiss to his lips. "Have a good day, baby. Love you."

"Love you too."

He wasn't going to get back to sleep anytime soon. He carefully extricated himself from Dean and went to brush his teeth.

When he came back into the bedroom, it was to Dean mumbling something unintelligible. The blankets moved in such a way it was immediately apparent he'd gotten hard, and Cas idly wondered if he should be offended that didn't happen until after he'd left the bed. Sam rolling over, dragging the blankets completely off his brother and giving Cas a perfect view of Dean's ass, derailed that train of thought.

How much could Dean take before he woke up? It was an intriguing thought, and not one that had crossed his mind before. He grabbed the lube from the nightstand and settled on the bed, careful not to touch until he slicked up a finger and carefully rubbed Dean's hole.

Dean muttered and humped back, clearly enjoying himself, and Cas eased it inside. He was still kind of loose from where he and Sam had fucked him the night before - and Cas had honestly never thought he'd be grateful for witches, but there was no denying the aphrodisiac they'd been hit with so long ago had done amazing things for their libidoes even after the immediate effects had worn off - and so there was little resistance as Cas rubbed and prodded. A few minutes later he slicked up his middle finger and pressed it inside next to his index, crooking and rubbing, watching Dean's face.

Sam sat up and took a breath as if to speak; Cas held a finger to his lips for quiet and leaned over Dean to whisper in Sam's ear, "How much until he wakes up?"

Sam smiled slowly, showing all his teeth, and settled back to watch the rim of Dean's ass sucking Cas's fingers in. When Cas judged him stretched enough, he added a third. Dean was moving more, humping back onto Cas's fingers, but his face was still slack. Sam bit his arm to keep from sniggering at how much of a cockslut Dean was, eager for it even in sleep.

Cas thought about replacing his fingers with his dick, but the point was to see how far he could get without waking Dean, so he worked his pinky in beside the other three fingers, pushing them in and out, opening and closing them slowly.

Dean slumbered on, or maybe he was just pretending to. Cas couldn't tell anymore.

He kept his fingers in place while he slicked up his dick, removing them only when he was lined up, and then pressed in slowly, biting his bottom lip to keep from making too much noise. Sam's eyes were dark when Cas glanced at him, hand wrapped loosely around his hard dick, and Cas pointed to Dean's head with a smirk. Sam grinned and moved slowly up the bed, but he didn't shove himself into his brother's mouth quite yet.

Cas eased further inside until his hips were flush with Dean's ass and leaned down to check. Dean really was doing a phenomenal job of pretending to be asleep, but the skin around his eyes was tight and he'd stopped moving his hips.

"We know you're awake, Dean," Sam said, voice low. "It's no use pretending."

Dean's eyes opened and he smiled up at them sleepily. "Feels good."

"How long have you been awake?" Cas asked quietly, starting to move in and out. Dean's ass clenched around him, tight and slick and sweet.

"Mm, second finger."

"Second finger?" Cas had the sneaking suspicion he was lying. "So how many fingers did I put in to stretch you out?"

"Three," Dean sighed. "Just like you always do."

Sam chuckled darkly. "Been awake since the second finger, huh?" His hand fisted in Dean's hair, longer than it had been when Cas had first met him, and yanked. Dean's head jerked to where Sam wanted it. "Nice try. You know how we feel about lying."

Cas's hand hit Dean's ass firmly, making him whine and push back. "Sam," Dean said.

Sam sighed and pushed his hips forward. Dean wrapped his lips around the head. Cas continued to push in and pull out, kneading the flesh of Dean's ass, enjoying the feeling of fucking him.

None of them lasted long, this early in the morning, and it was barely five minutes after Dean woke up that Cas slotted himself in deep and came, biting at Dean's shoulder and then pulling out to push Dean onto his back and stroke his dick. Sam and Dean came at nearly the same moment.

"I'm gonna get a shower," Dean said when he caught his breath again. "Anyone else coming in?"

"Mm, nope," Sam said, laying back down and pulling the covers up to his shoulder. "I have another hour before I have to get up."

"I'll join you," Cas said.

They didn't fool around any more in the shower, focusing instead of scrubbing the morning's activities from their skin. When they finally shut the water off, Dean pressed his lips to Cas's in a bruising kiss. "Just so you know," he said quietly, "you ever wanna do that again, I'm game."

Cas smiled. "We'll see what happens. I am too, for the record."

Dean laughed and kissed him again, more gently this time. "I'll get the kids up if you make breakfast."

"Happily."

By far, the best part of his life was the sheer _physicality_ of it. Angels had no physical form, did not even exist in the same form as sunlight - they were radiation, they were sound, but they were not light. There were no particles to give them form, merely waves of meaning and intent that shaped the world as they wished. Humans tended to perceive them as overwhelming light and sound in the brief moments before their eyes and ears melted before the existence of that which they were not built to see. It wasn't until Castiel had taken Jimmy Novak's body - a truly devout man, who had not flinched when Cas had explained to him so many years back that he was a warrior and so Jimmy may see Heavenly battle, who had said yes knowing Cas was not what modern Christianity called him, who had agreed to house him because Jimmy was righteous and he was good; Cas had visited him once in Heaven, not stupid enough to allow Jimmy's soul to see his form, and it soothed the sting of what he had done, at least a little - that he learned how precious touch was.

Even so, it had taken him some time. He'd had difficulty gauging how much force to exert, at least at first, and when he'd first lain with humans he'd had to heal Sam or Dean often, but they'd never complained. Cas always numbed the pain before they even realized it was there, fixed the damage before the slow-working nerves of the human body could tell the brain there was an injury to be fixed. He had gotten better over time.

But now, without his Grace informing his every move, Cas was free to move as he wished without fear. He could scoop his children from their beds and toss them into the air, knowing they wouldn't go through the ceiling. He could hold a partner close and be certain he would not break their ribs. He could kiss one of them without worrying about breaking their jaw.

And it was _pleasurable_. It was lovely, to touch people. The casual brushing of a hand over hair, heads in laps as they lay piled together watching a movie, bodies thrown over each other in a panting, sweaty post-coital tangle of limbs, a kiss on the side of his mouth. Those touches meant as much to him as the ones meant to be sexual, and he gave them as much as he could. Dean, too, was physical. Sam and Maria tended more toward words.

Cas was still considering the effects losing his Grace had had on him when class let out that night and Lucia invited them all over to keep working on the project. They accepted, and before long they were pulling up to an apartment complex in the middle of a town an hour away from the house he shared.

Cas called when he parked, still too unsure of himself to risk operating a car and a phone at the same time. Maria picked up on the second ring. "Hey, babe, what's up?"

"I wanted to let you know I'd be late tonight," Cas told her. "I'm working on a project for my math class."

"Have fun with that. Should I keep dinner for you or put it away?"

Cas considered. "It's likely to be at least three hours until I'm home."

"All right, it'll be in the fridge for you. Do you mind picking up milk on your way home?"

"Of course. Love you."

"Love you too, Cas. See you when you get home."

"See you then." He ended the call and joined his group on the sidewalk.

"Calling the old lady?" John asked.

Cas blinked at him. "Old lady?"

"He means your wife," Johanna explained.

"Oh. Yes. She gets worried if I'm late."

"What a control freak," Lucia said.

Cas frowned. "Shall we begin work on the project before it becomes too late?"

He'd noticed, and his partners had pointed out, that when he got uncomfortable he became very formal. It was one of the most striking ways he had to manage his emotions, which he was still often unsure how to handle.

An hour and a half after they began, Johanna stood and stretched. "Fun as this has been," she said vaguely sarcastically, "I should get home. I have work early tomorrow."

Mark stood, too. "I'll walk you out." He and Johanna were gone before Cas could process that they were leaving.

Lucia snorted. "They must think we're blind."

Cas considered. "Perhaps. Let me help you clean this up."

There were papers everywhere, notes in Mark's gigantic scribbly pencil and Johanna's loopier, more compact pen mingling with the stark black print of the assignment handout they'd left behind in the rush to leave. Combined with those were various notes they'd all made through the evening, scratching out authors and dates of research papers, theories they needed to include in the presentation next Monday, and more general notes about what someone had suggested. Between the two of them, they got it into a reasonably neat stack before Cas himself gathered his notebook. Lucia followed him to the door and opened it for him, but before she closed it, she said, "Hey, Cas."

He turned back to face her. "Yes?"

She bit her lip. "Do you think I'm pretty?"

"Um." He peered at her face. "I suppose so?"

"Good. Cause you're pretty, too." She took a step inside his personal space and stood on her toes.

For whatever reason, he didn't understand what she was planning until she did it, grabbing his head and yanking him down further to kiss him. Even then it took him a second or two for his brain to catch up and decide what to do about it. His hands came up to grip her shoulders and he pushed her firmly away.

"What?" she demanded.

Cas frowned at her. "I'm married. Happily. With children."

"But you think I'm pretty."

He scowled, any willingness he might have had to chalk it up to a misunderstanding on her part evaporating. "That does not mean I wish to kiss you. Good-bye, Lucia."

He turned and walked away, emotions he couldn't name bubbling to the surface and he shoved them away in favor of ones he _could_ understand. Primarily there was anger, tinting his vision red - anger wasn't a strong enough word for it. Rage? Fury? Fury was good, a good word, a furious tempest howling around him.

Then was disbelief, but not the kind he'd had when Maria had come home and told him she was carrying twins. This was a different kind, heavy in his stomach, weighing him down as he started the car.

Disgust, much the same as when he'd first tried yogurt. Disdain for the girl who had kissed him and made him an unwilling adulterer. Another, deeper layer of anger, leftover from his millennia of existence before he had even considered taking a vessel - she'd dared to assault a warrior of Heaven, and part of his being screamed for her to burn from holy wrath. Guilt that he might have led her on. Worry of what his partners would think of him now. And those were just the ones he could name.

Sometimes being human was horrible.


	2. Redemption

When he walked in the door, milk in hand, it was to the sound of Sam and Dean putting the kids to bed while Maria did dishes. He slid up behind her, put the milk on the counter next to the sink, and wrapped his arms around her waist, dropping his head to press his lips to her hair.

"Hey, Cas," she said, twisting and smiling awkwardly up at him. Her neck cracked at the movement; she didn't seem to notice. She looked tired beneath her make-up. "Wasn't expecting you for another few hours."

"Something came up."

"Yeah? What happened?"

He pulled away reluctantly. "I should tell you all at once. Repeating it would be unpleasant."

She stiffened. "That bad?"

"Yes."

"Then put away the milk and we'll talk when Sam and Dean are out."

Cas did as he was told.

When they were settled in the living room, Maria said, "So what happened?"

He looked at his hands, unable to see the others' faces. He'd Fallen for them, and then he'd allowed someone else to put hands on him. "Lucia kissed me."

"What?" Dean roared. Cas flinched away, though he missed Maria doing the same.

"Dean," Sam said sharply. "Cas, what _happened?_ "

The disappointment in his voice was almost too much for him to bear. "I was leaving. She asked if she was pretty, and I said I supposed so, and she kissed me. I pushed her away, but-"

"That absolute fucker," Dean growled. "I'm going to kill her."

"Dean," Sam said again.

"Did you want to kiss her?" Maria asked suddenly.

Cas's head popped up. "I - no! Of _course_ I didn't!"

She nodded, like she'd known that's what he'd say ( _She's your wife,_ he thought, _of course she knew that_ ), and looked back at Sam and Dean, who were having one of the silent conversations he still couldn't quite decode. It ended when Dean rolled his eyes and flopped back onto the couch next to his brother, huffing a breath and crossing his arms like a petulant teenager.

Sam looked at Cas, clearly at a loss for words. He knew it. He'd blown it. In a moment of weakness, he'd allowed himself to be kissed and everything was over. "I-" Sam started, then stopped, mouth opening and closing.

Maria sighed. "And somehow I ended up the healthy one in this relationship," she grumbled, scooching forward on her chair. "Cas. Look. You didn't want it. It'd be stupid to blame you."

"But?" he prompted when she paused. It was written all over her face.

She sighed. "But knowing it's stupid doesn't - aw, fuck it. You got a good enough grip on the emotions crap at this point, you know what I'm trying to say."

" _I_ don't even know what you're trying to say," Sam said.

She flushed red. "I'm hurt," she grumbled. "It's stupid, but I'm angry. At her, Cas, not you. Sam? What's going on with you?"

It was a transparent attempt to get the focus off her, but it worked. Sam leaned forward, arms braced on his knees, and said, "Little angry. Little jealous. Dean?"

"Oh, I am _furious,_ " Dean growled. "Someone else kissed my husband."

Something in Cas's chest jolted. It was the first time Dean had called him that to his face. "Dean," he said quietly. "I'm sorry."

"Not you I'm angry with," he growled. "But - Jesus, Cas, why didn't you push her away?"

"I did," Cas protested. "I pushed her away and told her to stop and then I left."

Dean sighed and looked down. Sam took his hand with one of his own and rubbed his eyes with the other.

Most of the time, Cas knew them. He knew how they'd react. He knew not to yell around Maria, he knew yelling at Dean was subliminally _This is important and you need to listen_ , he knew yelling at Sam would hurt him no matter how reasonable he tried to be. He knew what foods they liked, the alcohol they preferred, the songs they listened to when they were happy or angry or just sad. He knew their insecurities and their prides. He knew straight apologies worked with Sam, that talking things through fixed things with Maria, that only time would heal Dean (although sex helped sooth the wounds). He knew _them_. But this - this was something he _didn't_ know. He didn't know how to make this right. It was a situation it had never occurred to worry about because it had never occurred to him that it might happen.

Maria sat next to him and said softly, "It'll be okay, Cas." She kissed the knuckles of his hand, intertwined with hers - when had that happened and why hadn't he noticed? "We'll work it out. You told us."

"Better than keeping it to yourself," Sam agreed.

"I love you," he said.

"Love you too, baby," Maria said. There was still hut written all over her face, but she was trying to put it aside. For _him_. He had betrayed their vows, and she was prioritizing him. It didn't make sense.

Dean growled something unintelligible and said, "We're just going to have to remind you who you belong to."

There was a gleam in his eye that sparked an answering gleam in Sam's. Maria kissed him, slow and deep and so much better than anything he ever could have had with any other woman.

Sam and Dean stripped the shirt from his body and pushed him back until he was lying flat on their bed. His hands were tied above his head with cord taken from the garage - usually they used a bathrobe tie, when they did this, but Cas understood. The coarseness was his punishment for allowing it to happen.

They took their time. Dean was usually harsher, more demanding, making it clear he'd messed up, but he was as slow as Sam, licking over Cas's skin and his hands moving everywhere. "You're ours," Sam told him. "You're ours, and we're yours, and we're going to remind you of that."

There was a tremble in Sam's voice, and his eyes were mysteriously bright. Cas longed to touch him, to hold him, even to kiss him, but he could do nothing. 

Maria joined them, settling next to them on the bed and kissing Cas's forehead. "Nobody else," she whispered to him.

"No," he whispered back.

Her eyebrows did a convoluted squiggle - was she confused? What had he done wrong? - and settled. Her hand stroked through his hair.

One of his men pressed inside his ass and he arched, hissing. Dean engulfed his dick with his mouth and sucked gently. Maria stroked his face and hair and chest, eyes roving over him, never stopping anywhere for long. The finger in his ass became two fingers, then three.

Dean pulled off with a long, slow drag of his lips and gestured to Maria. Sam slipped inside him easily; Maria sat on Cas's dick and moved up and down. Dean sat on his face, dick pushing insistently down his throat.

They were slow, tonight. They weren't gentle, by any means - Sam's thrusts inside his ass were hard and punishing, Dean cut off his air for longer than Cas had thought he could manage without passing out, and Maria pinched and slapped him at random - but they were _slow._ Cas understood. As well as the coarse cord, this was his penance. Part of his penance, anyway; thinking nothing would change was folly. He had hurt them, badly, striking at the core of their shared life in a way unthinkable to them all.

Sam spilled inside him, wetness filling him, claiming him, marking him as theirs, and pleasure pooled in his lower belly. Dean filled his stomach soon after, adding his own brand to Castiel's body and intensifying the tightness in Cas's abdomen. Maria rippled and clenched around him, unable to fill him inside but marking his skin with her cum as well as the small bruises she had left during the act itself. Her orgasm caused his, and he grunted as he came.

Hands untied him busily, and three mouths attacked his at the same time, the four of them kissing awkwardly and sloppily, air separating their mouths but breaths mingling.

They slept that night in a pile, arms thrown possessively over each other. Maria cuddled into Cas's right side, Sam and Dean on his left, and Cas accepted the arms and legs tangling with his.

They were his, and he was theirs, and they would get through this.

**Notes for the Chapter:**

> I'm so sorry for the long wait! This was hard to write, for a lot of reasons, and most my chronic health issues came up (and I added a few new ones to repertoire! Funsies!), and college happened (I graduated last weekend! Finally!) and just...IDK. Lots of shit happened.
> 
> On the bright side, the next wait shouldn't be so long. I know exactly how I want that to go, and a canon character will be returning, and it'll be good and fluffy and happy. (Unless I write a chapter that's just Dean and Cas in bed right after this one ended. That's really tempting. There's not a whole lot of angry sex, in this series, and while that's good, angry sex and mild punishment could be fun to try to write. (Did I mention 'Good Girl' was the first porny thing I wrote? Because it was, and I was worried about the response, and then it became...this.)
> 
> Anyway! As always, please review.


End file.
